Breastfeeding of infants has long been hailed as the best way to give babies the nutrients they need. Now a new study shows it may provide an important health benefit to mothers. As Amy Katz reports, the study says nursing may reduce a woman's risk of developing diabetes in the future.

Alison Cape has been breastfeeding her daughter Charlotte since she was born. "I am planning on breastfeeding until I cannot do it any longer,” she says, “which, I am hoping to go a full year, as I work, you know. I'll go as far as I can."

If she really does breastfeed her daughter for a full year, she could dramatically reduce her own risk of developing diabetes later in life, according to Dr. Alison Stuebe.

"We looked specifically at women in the 15 years after they had their last baby, and we found that each year a woman breastfeeds reduced her risk of diabetes by 15 percent," says the doctor.

Dr. Stuebe and her colleagues at Brigham and Women's Hospital in Boston tracked the health and breastfeeding practices of 150,000 women for the study, which appeared in a recent edition of JAMA, the Journal of the American Medical Association. The study also showed that women who breastfed exclusively -- feeding their babies nothing but breast milk -- got more benefit than those women who fed their babies breast milk along with formula or food. Breastfeeding may affect the risk of diabetes because it can help prevent weight gain.

"A breastfeeding woman uses up about 500 calories a day making milk for her baby,” says Dr. Stuebe. “That is the equivalent of running about four to five miles a day."

"It is just another incentive for people to keep breastfeeding and it certainly reinforces my decision to do so," adds Alison.

For both Alison and Charlotte Cape, it is a decision that will likely have lifelong benefits.